Poster: Emerging Technologies

Abs # 896: Development of Protoporphyrinogen Oxidase as a Selection Marker for Agrobacterium Transformation of Maize to Confer Field Tolerance to Butafenacil

Presenter:	Li, Xianggan , Xianggan.li@syngenta.com
Authors	Li, Xianggan  (A)   Volrath, Sandy  (B)   Nicholl, David  (A)   Chicott, Charles  (A)   Johnson, Marie  (A)   Ward, Eric  (B)   Law, Marc  (A)
Affiliations:	(A): Syngenta Biotechnology, Inc. North Carolina 27709-2257, USA (B): CropSolution, Inc., NC 27560, USA

In this poster, we report the isolation of plant protoporphyrinogen oxidase (PPO) genes and the isolation of herbicide tolerant mutants. Subsequently, a PPO mutant was used to develop a selection marker system for Agrobacterium transformation of maize and to obtain multiple events tolerant to the PPO family of herbicides. Maize transformants were produced via butafenacil selection using a flexible light regime to increase selection pressure. Butafenacil selection did not change the copy number distribution of the transgene, although the most tolerant events identified in the greenhouse were more likely to contain multiple copies of the transgene. The high efficiency of Agrobacterium transformation via PPO selection enabled us to obtain single copy transgenic maize lines tolerant to field levels of butafenacil.